1. Field of the Invention
The invention relates to a switch, and more particularly to a temperature switch that may cut off power supply of an electric device when an abnormal temperature condition exists.
2. Description of the Related Art
A common electrical appliance configured for heating, such as a water dispenser, a coffeemaker, an electrical iron, a hairdryer, etc., employs a heater for heating.
Such an electrical appliance usually includes a temperature switch and a fuse to keep a desired temperature and to prevent danger resulting from abnormal operation of the heater. Although safety may be ensured, installation of the two components (i.e., the temperature switch and the fuse) in a limited space of the electrical appliance may disfavor assembly process. Referring to FIGS. 1 and 2, commonly owned co-pending U.S. patent application Ser. No. 13/406,946 discloses a temperature switch 1 that abuts against a heating component 10, that electrically interconnects two wires 11, and that includes a base 12, a conducting mechanism 13 and a temperature control mechanism 14.
The base 12 includes a base body 121, and a cap body 123 that is connected to the base body 121 to form an accommodating chamber 122 therebetween and that has a limiting hole 124. The conducting mechanism 13 includes two conducting pieces 131, 132 respectively and electrically connected to the wires 11, a fixed conducting rod 133 installed on the base body 121 and electrically connected to the conducting piece 131, a conducting resilient piece 135 installed within the accommodating chamber 122 via a coupling component 134, and two fuses 136 electrically interconnecting the conducting piece 132 and the conducting resilient piece 135. The temperature control mechanism 14 includes a temperature sensing cap 142 that cooperates with the cap body 123 to form a deformation space 141, a temperature-sensing control plate 143 disposed in the deformation space 141, and a linking rod 144 disposed movably in the limiting hole 124. The linking rod 144 is biased between the temperature-sensing control plate 143 and the conducting resilient piece 135.
In a normal operation state, the linking rod 144 is biased by the temperature-sensing control plate 143, such that the conducting resilient piece 135 is biased to abut against the fixed conducting rod 133, thereby permitting current flow through the conducting piece 131, the fixed conducting rod 133, the conducting resilient piece 135, the fuses 136, and the conducting piece 132. When the heating component 10 reaches a specified temperature, the temperature-sensing control plate 143 deforms as shown in FIG. 2, and the conducting resilient piece 135 restores and is separated from the fixed conducting rod 133. When the temperature is abnormally high, and the temperature-sensing control plate 143 is disabled from deformation or the conducting resilient piece 135 loses its restoring ability, the fuses 136 are melted, so as to cut off current flow between the conducting piece 132 and the conducting resilient piece 135.
Ideally, the aforesaid temperature switch 1 may ensure safety. However, in practice, since each of the fuses 136 stands as a pillar, the fuses 136 are apt to melt incompletely, thereby failing to break electrical connection.